Physiological and evolutionary contexts of a new symbiotic species from the nitrogen-recycling gut community of turtle ants.

While genome sequencing has expanded our knowledge of symbiosis, role assignment within multi-species microbiomes remains challenging due to genomic redundancy and the uncertainties of in vivo impacts. We address such questions, here, for a specialized nitrogen (N) recycling microbiome of turtle ants, describing a new genus and species of gut symbiont-Ischyrobacter davidsoniae (Betaproteobacteria: Burkholderiales: Alcaligenaceae)-and its in vivo physiological context. A re-analysis of amplicon sequencing data, with precisely assigned Ischyrobacter reads, revealed a seemingly ubiquitous distribution across the turtle ant genus Cephalotes, suggesting ≥50 million years since domestication. Through new genome sequencing, we also show that divergent I. davidsoniae lineages are conserved in their uricolytic and urea-generating capacities. With phylogenetically refined definitions of Ischyrobacter and separately domesticated Burkholderiales symbionts, our FISH microscopy revealed a distinct niche for I. davidsoniae, with dense populations at the anterior ileum. Being positioned at the site of host N-waste delivery, in vivo metatranscriptomics and metabolomics further implicate I. davidsoniae within a symbiont-autonomous N-recycling pathway. While encoding much of this pathway, I. davidsoniae expressed only a subset of the requisite steps in mature adult workers, including the penultimate step deriving urea from allantoate. The remaining steps were expressed by other specialized gut symbionts. Collectively, this assemblage converts inosine, made from midgut symbionts, into urea and ammonia in the hindgut. With urea supporting host amino acid budgets and cuticle synthesis, and with the ancient nature of other active N-recyclers discovered here, I. davidsoniae emerges as a central player in a conserved and impactful, multipartite symbiosis.

Perioperative Opioid Exposure Patterns in Pediatric Anterior Cruciate Ligament Reconstruction: A Ten-Year Administrative Database Study.

INTRODUCTION: Variation in opioid exposure has been documented in many pediatric fields; however, little is currently known about the extent of these findings during the perioperative period. The purpose of this study was to examine perioperative opioid exposure on a national level among patients undergoing anterior cruciate ligament (ACL) reconstruction using an administrative database. Our aims were to assess the impact of hospitals and a variety of demographic factors on (1) the likelihood of perioperative opioid exposure and (2) the variability in relative opioid exposure. METHODS: The Pediatric Health Information Systems Database (PHIS) was used to identify pediatric patients (≤ 18 years old) across 52 hospitals undergoing ACL reconstruction between January 2008 and December 2017. Administered opioids in morphine milligram equivalents were discretized into quintiles to represent relative opioid exposure (ROE). A hurdle generalized additive model was estimated to identify demographic factors predictive of (1) the receipt of any opioid medication and (2) the ROE among those receiving opioids. RESULTS: Of the 19,821 patients meeting study inclusion criteria, 17,350 (88%) were administered opioid medications perioperatively. There was no temporal trend in perioperative opioid utilization or ROE over the study period. Patients in an inpatient (OR = 0.260 [0.221, 0.305]) or observation unit (OR = 0.349 [0.305, 0.401]) context were less likely to be administered opioids. Female patients (OR = 0.896 [0.813, 0.987]) were less likely to be administered opioids, while patients on commercial insurance had a higher ROE (OR = 1.09 [1.023, 1.161]). Patient age and hospital-level time trends predicted opioid administration and exposure (max p < 0.001). DISCUSSION: Gender, age, surgical setting, hospital type, and insurance status, in part, predicted perioperative opioid exposure among pediatric patients undergoing ACL reconstruction surgery. Exposure has not declined in recent years and varies significantly between hospitals. Although this study primarily served to document demographic variability in perioperative opioid exposure in pediatric patients undergoing ACL reconstruction, the understanding of variability in perioperative opioid utilization and exposure rate could stand to be further explored.

Complete Genome Sequence of Cluster J Mycobacteriophage Superphikiman.

Mycobacteriophage Superphikiman is a cluster J bacteriophage which was isolated from soil collected in Philadelphia, PA. Superphikiman has a 109,799-bp genome with 239 predicted genes, including 2 tRNA genes.